1. Field
The aspects of the disclosed embodiments relate to a connecting piece, a multi-axis machining center comprising a connecting piece, and an elasticity control method.
2. Brief Description of Related Developments
Connecting pieces are used in order to have elasticity in the system in the case of collisions between the tool of the machine and other machine parts or the workpiece, so that damages due to rigid components are avoided. In this context “elasticity” does not necessarily mean a linear elasticity similar to a spring constant. Rather, a general flexibility under defined conditions is to be meant.
A known connecting piece comprises a support on the machining center side, a holder on the tool side and a clamping device which elastically pushes the holder into a defined position against the support. The clamping device comprises a plurality of pressure springs and tension springs, the tension of which can be adjusted by manually setting the spring preloads.
What is disadvantageous with regard to the known connecting pieces is that the system elasticity provided by them can only laboriously and, in operation, virtually not be changed. E.g., tool heads can have different weights, so that they show different inertial forces at the same acceleration. This also makes necessary different mounting forces, what can only be achieved by manual intervention. It can also be desirable to adjust the mounting force in dependence on the working mode. E.g., when a machining center is programmed, collisions are more likely to occur than during the subsequent operation, so that for the programming a lower system rigidity can be desired than is during the subsequent working. It can also be desirable to adjust the rigidity in dependence on the adjusting speed or the acceleration of a working head or tool. The position of the tool can also cause different torques and forces and, accordingly, different conditions with regard to the reaction of the connecting piece.